patch 8.2.3840: useless test for negative index in check functions

Problem:    Useless test for negative index in check functions.
Solution:   Remove the test for negative index. (Naruhiko Nishino,
            closes #9364)
diff --git a/src/version.c b/src/version.c
index be0122d..fc30b89 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3840,
+/**/
     3839,
 /**/
     3838,